The present invention relates to a roller or wheel on an input device, such as a mouse. In particular, it relates to providing a feedback force to the user of the roller.
A roller is typically used on a mouse in addition to the primary input which comes from moving the mouse around on a ball protruding from the bottom of the mouse housing. Alternately, an optical sensor may be used instead of a ball. Other input devices, such as a track ball with the ball on top, a joystick, etc., will have a movable portion for providing the input. In addition to this movable portion, a roller may be added as well. The roller can be used for such functions as scrolling or zooming. The roller is operated by a user""s finger, much like a dial on a radio.
There are a number of different designs for such rollers on a mouse or other device. Examples include Multipoint Technology Corporation U.S. Pat. No. 5,298,919, Microsoft U.S. Pat. No. 5,473,344, Apple Computer U.S. Pat. Nos. 5,313,230 and 5,095,303, Mouse Systems U.S. Pat. Nos. 5,530,455 and 5,446,481, Primax Electronics U.S. Pat. No. 5,808,568, and Logitech U.S. Pat. No. 6,157,369.
Force feedback has been used in different input devices, including mice. Examples of force feedback mechanisms can be found in a number of patents assigned to Immersion Corporation, such as U.S. Pat. No. 5,825,303, No. 5,734,373, No. 5,767,839, No. 5,721,566, No. 5,805,140, No. 5,691,898 and No. 5,828,197.
Immersion Corporation U.S. Pat. No. 6,128,006 describes force feedback on a mouse wheel (roller). The mechanism shown is a motor either directly connected to the axle of the mouse wheel, or a pulley drive coupled to the axle. A passive actuator such as a magnetic particle brake or a friction brake is discussed.
U.S. Pat. No. 6,128,006 also describes a number of different types of feedback. The feedback can be provided to simulate the ratchet effect currently provided by mechanical spring-type mechanisms in mouse wheels. The feedback can also be used to provide user feedback when a line is crossed on a document on a display. Similar feedback can be provided for the end of the page or the end of a document. The patent also describes providing an amount of feedback which is related to the size of the document.
U.S. Pat. No. 6,128,006 also describes that when the wheel is used for a cursor, feedback can be provided on graphic items that the cursor passes over.
A disadvantage of force feedback is the power required to provide the force which is felt by the user. This is particularly problematic for a cordless mouse or other device which relies on batteries, or on a device which is powered off of the limited power from the universal serial bus (USB).
The present invention provides a roller on a mouse or other input device which can passively impart an effect to a user with low power. The invention uses an autoblocking mechanism, such as a brake, which derives its force from the force of the user""s finger pushing against the autoblocking mechanism. This provides an open-loop system which relies on the force of the user""s finger, and thus can operate at low power.
In one embodiment, a braking mechanism using two small rollers biased against the bigger roller or wheel is used. As the user applies a turning force to the wheel, it wedges against one of the two small rollers, depending on the direction, providing the feeling of resistance to the user as the wheel is turned. In an alternate embodiment, a brake shoe is rotated until it contacts the outside periphery of the wheel. Continued rotation of the wheel by the user provides the desired resistance, and rotates the brake shoe to change the contact point between the brake shoe and the wheel. The present invention advantageously uses the force from the user""s own finger to translate into a resistance signal, minimizing the amount of force needed to be provided by an electromagnet or motor.
In another embodiment of the invention, an open loop signal is used to provide a ratchet-type effect. In addition, instead of signals going to the host computer and then a force feedback signal being provided back to the mouse, the host is bypassed. This provides faster turnaround, which is important especially for a shared bus communication to the host. The wheel sensor signal indicating turning of the wheel is provided to a local processing circuit, which then activates the actuator for the resistance mechanism within the mouse at intervals corresponding to the amount of turning, to provide a ratchet feel.
For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings.